A typical folding stage system of the prior art is proposed in Japanese Application for Registration of Utility Model No. 52-82315 (published under No. 60-25482). The prior folding stage system has a guide post to be fixed to a wall or the like, and a balancer mechanism supporting the rear portion of the stage body for vertical movement The prior folding stage system also has, on its front portion, wheels to enable the stage body to be moved on a floor. The stage body of the system can be "folded" or stored from a horizontal position on the floor to a vertical position adjacent to the post. Legs are pivotally connected to the bottom of a platform so that the legs make right angles with the platform when supporting the platform on the floor, but change their angles to the platform as the legs are raised away from the floor when the stage body is moved to the vertical position, and become parallel to the platform when the platform is moved to a vertical position.
The inventor hereof proposed a folding stage system similar to the foregoing one in Japanese Application for Registration of Utility Model No. 59-100829 (published under No. 61-16200).
However, with the help of the balancer mechanism, either of the prior folding stage systems must be manually folded or unfolded. Also, the presence of the guide post and the balancer mechanism provided therein relatively complicates the construction of the whole system.